Applied Programming/RegEx/JavaScript
< Applied Programming | RegEx
regex.js edit
/* This program demonstrates regex and dictionary processing.
Input:
None
Output:
The cat in the hat.
{ the: 2, cat: 1, in: 1, hat: 1 }
cat: 1
hat: 1
in: 1
the: 2
References:
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/matchAll
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/for...in
*/
if (typeof module != "undefined" && !module.parent) {
main();
}
/**
* Runs main program logic.
*/
function main() {
const text = "The cat in the hat.";
console.log(text);
let wordCount = getWordCount(text);
console.log(wordCount);
displayWordCount(wordCount);
}
/**
* Processes text and returns word counts.
*
* @param {string} text words to process
* @returns {object} words and count
*/
function getWordCount(text) {
const pattern = /\w+/g
const matches = text.matchAll(pattern);
let wordCount = {};
for(const match of matches) {
const word = match[0].toLowerCase();
if (word in wordCount == false) {
wordCount[word] = 0;
}
wordCount[word] += 1;
}
return wordCount;
}
/**
* Displays word counts.
*
* @param {object} words and count
*/
function displayWordCount(wordCount) {
const words = Object.keys(wordCount).sort();
for (const word of words) {
console.log(`${word}: ${wordCount[word]}`);
}
}
/**
* Input function to get input in Node environment.
*
* @param {string} text prompt
* @returns {string} input
*/
function prompt(text) {
const rls = require('readline-sync');
let value = rls.question(text);
return value;
}
Try It edit
Copy and paste the code above into one of the following free online development environments or use your own JavaScript compiler / interpreter / IDE.